Motorcycle exhaust system



FIG. 1 is a right side perspective view of a motorcycle exhaust system showing my new design;

FIG. 2 is a right side perspective view thereof on a greatly reduced scale, shown in position of use on a motorcycle;

FIG. 3 is an enlarged, detailed view of FIG. 2;

FIG. 4 is a left side perspective view of FIG. 1;

FIG. 5 is a front perspective view of FIG. 1; and,

FIG. 6 is a rear perspective view of FIG. 1.

The broken lines shown are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a motorcycle exhaust system, as shown and described. 